/// <summary>
/// Primitive patching. Inserts a jump to 'target' at 'site'. Works even if both methods'
/// callers have already been compiled.
/// </summary>
/// <param name="site"></param>
/// <param name="target"></param>
public static RedirectCallsState PatchJumpTo(IntPtr site, IntPtr target)
{
RedirectCallsState state = new RedirectCallsState();
// R11 is volatile.
unsafe
{
byte* sitePtr = (byte*)site.ToPointer();
state.a = *sitePtr;
state.b = *(sitePtr + 1);
state.c = *(sitePtr + 10);
state.d = *(sitePtr + 11);
state.e = *(sitePtr + 12);
state.f = *((ulong*)(sitePtr + 2));
*sitePtr = 0x49; // mov r11, target
*(sitePtr + 1) = 0xBB;
*((ulong*)(sitePtr + 2)) = (ulong)target.ToInt64();
*(sitePtr + 10) = 0x41; // jmp r11
*(sitePtr + 11) = 0xFF;
*(sitePtr + 12) = 0xE3;
}
return state;
}
public static void Deploy()
{
if (!deployed)
{
_InitializePrefab_original = typeof(BuildingInfo).GetMethod("InitializePrefab", BindingFlags.Instance | BindingFlags.Public);
_InitializePrefab_detour = typeof(BuildingInfoDetour).GetMethod("InitializePrefab", BindingFlags.Instance | BindingFlags.Public);
_InitializePrefab_state = RedirectionHelper.RedirectCalls(_InitializePrefab_original, _InitializePrefab_detour);
deployed = true;
BetterUpgradeMod.debugLog.Add("Better Upgrade: BuildingInfo Methods detoured!");
}
}
public static void Deploy()
{
if (!deployed)
{
try {
_PrivateBuildingAI_StartUpgrading_original = typeof(PrivateBuildingAI).GetMethod("StartUpgrading", BindingFlags.Instance | BindingFlags.NonPublic);
_PrivateBuildingAI_StartUpgrading_detour = typeof(PrivateBuildingAIDetour).GetMethod("StartUpgrading", BindingFlags.Instance | BindingFlags.NonPublic);
_PrivateBuildingAI_StartUpgrading_state = RedirectionHelper.RedirectCalls(_PrivateBuildingAI_StartUpgrading_original, _PrivateBuildingAI_StartUpgrading_detour);
}
catch (Exception e)
{
BetterUpgradeMod.debugLog.Add("Detour 0 failed: " + e.Message + ":" + e.StackTrace);
}
deployed = true;
BetterUpgradeMod.debugLog.Add("Better Upgrade: PrivateBuildingAI Methods detoured!");
}
}
public static void RevertRedirect(MethodInfo from, RedirectCallsState state)
{
var fptr1 = from.MethodHandle.GetFunctionPointer();
RevertJumpTo(fptr1, state);
}
public static void RevertJumpTo(IntPtr site, RedirectCallsState state)
{
unsafe
{
byte* sitePtr = (byte*)site.ToPointer();
*sitePtr = state.a; // mov r11, target
*(sitePtr + 1) = state.b;
*((ulong*)(sitePtr + 2)) = state.f;
*(sitePtr + 10) = state.c; // jmp r11
*(sitePtr + 11) = state.d;
*(sitePtr + 12) = state.e;
}
}